package com.disktalk.util;

import java.security.MessageDigest;

public class MD5Util {

	/**
	 * 加密解密算法 执行一次加密，两次解密
	 * 
	 * @param inStr
	 * @return
	 */
	public static String convertMD5(String inStr) {
		char[] a = inStr.toCharArray();
		for (int i = 0; i < a.length; i++) {
			a[i] = (char) (a[i] ^ 't');
		}
		String s = new String(a);
		return s;
	}
	
	
	/**
	 *  MD5加码 生成32位md5码
	 * @param inStr
	 * @return
	 */
	  public static String string2MD5(String inStr){
	    MessageDigest md5 = null;
	    try{
	      md5 = MessageDigest.getInstance("MD5");
	    }catch (Exception e){
	      System.out.println(e.toString());
	      e.printStackTrace();
	      return "";
	    }
	    char[] charArray = inStr.toCharArray();
	    byte[] byteArray = new byte[charArray.length];

	    for (int i = 0; i < charArray.length; i++)
	      byteArray[i] = (byte) charArray[i];
	    byte[] md5Bytes = md5.digest(byteArray);
	    StringBuffer hexValue = new StringBuffer();
	    for (int i = 0; i < md5Bytes.length; i++){
	      int val = ((int) md5Bytes[i]) & 0xff;
	      if (val < 16)
	        hexValue.append("0");
	      hexValue.append(Integer.toHexString(val));
	    }
	    return hexValue.toString();

	  }
	
	// 测试主函数
	  public static void main(String args[]) {
	    String s = new String("?name=chen");
	    System.out.println("原始：" + s);
	    System.out.println("MD5后：" + string2MD5(s));
	    System.out.println("加密的：" + convertMD5(s));
	    System.out.println("解密的：" + convertMD5(convertMD5(s)));
	  }

}
